(Ni3–xMgx)[B3P3O12(OH)6] · 6 H2O (x ≈ 1.5): A Novel BorophosphateHydrate Containing Isolated Six-Membered Rings of Tetrahedra

✍ Scribed by Insan Boy; Gerd Schäfer; Rüdiger Kniep

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: German
• Weight: 180 KB
• Volume: 627
• Category: Article
• ISSN: 0372-7874
• DOI: 10.1002/1521-3749(200102)627:2<139::aid-zaac139>3.0.co;2-4

✦ Synopsis

A novel borophosphate-hydrate, (Ni 3±x Mg x )-[B 3 P 3 O 12 (OH) 6 ] ´6 H 2 O (x » 1.5), has been prepared by hydrothermal synthesis (T = 170 °C) from a mixture of NiCl 2 ´6 H 2 O, Mg(OH) 2 , B 2 O 3 and H 3 PO 4 . The crystal structure was determined at 293 K from single-crystal X-ray diffraction data (trigonal, R3c (no. 167), a = 14.957(10) A Ê , c = 13.812(6) A Ê , V = 2676(2) A Ê 3 , Z = 6, R 1 = 0.0276, wR 2 = 0.0714 for 779 observed reflections with I > 2r(I)). The crystal structure contains unbranched six-membered rings [B 3 P 3 O 12 (OH) 6 ] 6± of alternating corner linked borate and phosphate tetrahedra, which are stacked along [001] and connected via M II O 2 (OH) 2 (H 2 O) 2 coordination polyhedra. Hydrogen bonding between the tetrahedral six-membered rings and M II O 2 (OH) 2 (H 2 O) 2 octahedra leads to a further cross-linking. With respect to the arrangement of isolated six-membered tetrahedral rings the crystal structure of this borophosphate-hydrate is closely related to the cyclo-hexasilicate dioptase, Cu 6 [Si 6 O 18 ] ´6 H 2 O.